The al-Qaida takeover of parts of Iraq's Anbar province, where about a third of American troops killed in the war perished, has left area Iraq War veterans bitterly wondering what their sacrifice was all about.
"It's disheartening," said Francis Romanitch, 28, a Marine Corps reservist who served in the Anbar city of Ramadi in 2004 as Marines fought door-to-door 25 miles away in Fallujah.
"For all the blood that was shed, to see it fall, it's like seeing the Japanese flag flying over Iwo Jima 10 years after World War II," said Romanitch, of Babylon.
Last week, al-Qaida-linked forces overran parts of Fallujah and Ramadi, commandeering police and military facilities, and setting up armed checkpoints. The White House has ruled out resending U.S. troops -- who withdrew from Iraq in 2011 -- but is providing the Iraqi government with arms.
Beginning in 2004, Anbar, a Sunni power base for Iraqi dictator Saddam Hussein before his capture, became the scene of some of the bloodiest confrontations during the war.
After insurgents hung the burned bodies of four American contractors from a bridge in Fallujah, U.S. troops that April rooted out opponents during weeks of door-to-door confrontations. But they paid a horrific price, according to historian Richard Lowry, author of the book "New Dawn: The Battles for Fallujah."
"These young Marines -- 19 years old -- went in every building and every room of Fallujah," Lowry told Fox News. "They entered darkened rooms, kicking down doors, never knowing if they would find an Iraqi family hunkered down in fear or an Islamist terrorist waiting to shoot them and kill them. And they did that over and over and over again."
Mental health workers have said witnessing a military collapse can be emotionally traumatic for war veterans regardless of what conflict they fought in.
"It's re-traumatizing, if you will," said Denis Demers, who served as a psychological medic in Vietnam and now counsels veterans at the Suffolk Veterans Service Agency.
In 2004, Michael Posner was stationed in Mosul with a New York National Guard unit when a bomb ripped through a military mess tent, riddling him with shrapnel and killing 14 fellow soldiers. He said watching parts of Iraq slip under insurgent control weighs heavily on him.
"It brings back a lot of memories and flashbacks," said Posner, 43, of Bellport. Feelings of anxiety, depression and anger spawned by his wartime experience for a while pushed him to abuse alcohol and cost him his marriage.
"I lost a part of my soul over there," he said.
Posner, who since returning from Iraq has helped counsel fellow soldiers suffering from anxiety attacks, said he's recently received phone calls from veterans expressing rage.
"A lot of these guys lost a lot of their buddies and saw a lot of bloodshed," he said. "There was so much work they did, and it's gone to hell."
Scott Molloy, 29, of Kings Park, who served in Afghanistan in 2012, said the feeling of accomplishment he had over there has turned to disillusionment.
Molloy has struggled to control feelings of anger and frustration related to post-traumatic stress disorder. He said those feelings have worsened because of the al-Qaida surge.
"It hits you like a ton of bricks," he said. "You ask yourself, 'Why did I go through all that? Why am I suffering?' "